Barricade apparatus switch



Dec. 17, 1957 A. E. MARTIN ETAL BARRICADE APPARATUS swI'r'cH Original Filed Sept. 5, 1952 5 Sheets-Sheet 1 23 ALGY E- MART/N 8 MEARL' D. LOP/MOI? INVENTORS.

HUEBNER, BEEHLER, WORREL 8 HERZ/G,

ATTORNEYS- A. E. MARTIN EI'AL BARRICADE APPARATUS SWITCH Original Filed Sept. 5, 1952 Dec, 17, 1987 3 Sheets-Sheet 2 IN V EN TORS- MEARL D. LOP/MGR,

HUEBNER, BEE/'ILER WORREL 8 HERZ/G,

.4770 NErs. ZJM/lw T ALGY E-MARTIN 8 Dec. 17, 1957 A. E. MARTIN ETA].

BARRICADE APPARATUS swncn Original Filed Sept. 5. 1952 3 Sheets-Sheet 3 Amy E'- MARTIN a MEARL a. LOR/MOR,

IN V EN TORS.

HUEBNER BE'EHLER, WORREL 8 HERZ/G,

- ATT RNEYS. "Um T.

United States Patent-O 1 2,816,970 BARRICADE APPARATUS SWITCH Algy E. Martin, North Hollywood, and Mearl D. Lorimor,

Los Angeles, Calif., assignors to Light Products, Inc.,

Beverly Hills, Califi, a corporation of California Original application September 5, 1952, Serial No.

308,022, now Patent No. 2,800,601, dated July 23,

1957. Divided and this application April 5, 1954,

Serial No. 421,109

6 Claims. (Cl. 200-42) This invention relates to barricade apparatus, and more particularly to a barricade embodying a warning light and adapted to be placed temporarily in front of street excavations and obstacles to warn motorists of the hazard.

This is a division of United States patent application Serial No. 308,022 filed September 5, 1952, now Patent No. 2,800,601, issued July 23, 1957.

It is an object of this invention to provide a barricade embodying a flashing lamp capable of operating continuously and dependably over a long period of time and under all conditions of weather and handling.

It is a further object of this invention to provide a flashing warning light that will operate dependably both night and day.

It is another object of this invention to provide a discharge lamp adapted to continually and repetitively flash on and off, which will flash dependably both in the day and night, and which will stand the rigors of all kinds of weather.

It is a further object of this invention to provide means in a tubular discharge lamp for preventing the lamp from flashing erratically when subjected to continued repetitive flashing pulses of voltage, and to insure regular flashing with each ulse application.

It is another object of this invention to provide a unique shaft actuating mechanism by which the shaft may be turned only by a person having an appropriate tool.

More particularly, it is an object of this invention to provide switch actuating means by means of which the on and 01f switch for the above discussed flashing lamp may be operated from outside the lamp casing only by one having the special tool required.

It is a further object of this invention to provide a special switch as above set forth, in which the switch may be actuated from outside the lamp casing while still maintaining the casing substantially sealed again-st entry of water.

It is a further object of this invention to provide a barricade having improved means for securing a lamp thereto, and also for securing the barricade in extended position so that it may not be readily collapsed and stolen.

It is another object of this invention to make more diflicult the theft of a street barricade by providing simple and eifective means for locking the barricade legs in extended position, whereby portage of the barricade is made considerably more awkward, thereby discouraging theft thereof.

it is a further object of this invention to provide a collapsible structure such as a collapsible barricade, which may be readily extended to usable position, and in that position locked, thereby discouraging theft of the barricade.

It is another object of this invention to provide a barncade as above described, in which the means for locking the barricade legs in open position is simply and uniquely combined with means for securing a warning lamp or light to the barricade, whereby with a single lock a lamp may be secured to the barricade and the barricade may be Fig. 1 is a schematic circuit diagram of the flashing lamp forming a part of the instant invention.

Fig. 2 is a longitudinal elevational section of the operative portion of the lamp showing particularly the supporting chassis.

Fig. 3 is a top view of the electrical cell shown in Fig. 2.

Fig. 4 is a cross-section taken on the line 44 of Fig. 2.

Fig. 5 is an exploded perspective view of the lamp chassis.

Fig. 6 is a perspective view of a cover which protects and shields the operating portions of the lamp.

Fig. 7 is a fragmentary View taken on line 7-7 in Fig. 2.

Fig. 8 is another fragmentary view taken on line 8-8 of Fig. 2.

Fig. 9 is an elevational view of a modified form of discharge tube which may be used alternatively with the discharge tube shown in Figs. 2 and 4.

Fig. 10 is a perspective view of a grounding clip used on the tube of Fig. 9.

Fig. 11 is a perspective view showing a portion of a barricade constructed in accordance with the instant invention, and including the lam of the instant invention mounted thereon.

Fig. 12 is a fragmentary cross-section showing the unique on-oif switch of the instant invention, and taken along line 12-12 in Fig. 11.

Fig. 13 is a fragmentary perspective of the upper portion of the barricade legs shown in Fig. 11.

Fig. 14 is a fragmentary longitudinal section taken on line 14--14 of Fig. 11.

Fig. 15 shows a modified form of leg structure for the barricade, which may be used as an alternative to the structure shown in Fig. 11.

Referring to the drawings, the circuit of Fig. 1 illustrates a source of potential such as a dry cell 21, one terminal of which is connected, through an on-oif switch 22, to the lamp chassis represented by the ground 23. The other terminal of the cell 21 is connected to one side of the primary winding 24 of a step-up transformer 26. The other side of the winding 24 is connected to ground through an automatically operated intermittent switch 27. Shunting the switch 27 is a storage and spark-absorbing capacitor 28. The secondary winding 29 of the transformer 26 is connected across the respective electrodes of an electron discharge tube 31, one terminal of which is grounded to the chassis 23.

As will become apparent hereinafter in connection with the description of the physical structure, one arm of the switch 27 is so mounted with relation to the core of the transformer 26 that whenever there is a magnetic field in the core, the switch arm is pulled quickly toward the core, thereby pushing the other arm of the switch 27 away and opening the switch 27, against the normal bias of a hair spring.

The operation of the lamp circuit of Fig. 1 is as follows. When the on-ofi switch 22 is manually closed, current from the battery flows through the primary winding 24 and through the switch 27, which is normally biased closed. Energization of the transformer 26 pulls one arm of the switch 27 toward the transformer core, which pushes or shoves the other switch arm away from it and opens the switch 27. The sudden breaking of current in the transformer primary 24 induces a high voltage in the secondary winding 29, which appears across the discharge tube 31 and causes a flash of light. The arm of switch 27 which had previously been impelled away then returns to closed position, by virtue of the spring bias. The transformer 26 is re-energized and the cycle is repeated. While the above explanation is somewhat over simplified in view of the fact that there are actually several electrical oscillations across the secondary winding 29 with each opening of the switch 27, such detailed discussion of the circuit operation forms no part of the instant invention and will not be further discussed herein. 7

By suitable adjustment of the mechanical characteristics of the switch 27, the flashes of light emitted by the discharge tube 31 may be caused to occur with a frequency ranging from approximately 600 to 90 flashes per minute.

It will be noted at this point that since the voltage across the tube 31 is always generated by the breaking of a current flowing in a given direction in the primary winding 24, the average current flowing through the tube 31 has a D. C. value. That is to say, after any given flash through the tube 31 it will be found that much more current has flowed through the tube in one direction than in the other direction. This is because the major or largest pulse of voltage appearing across the tube 31 is unidirectional, and while trailing pulses of opposite voltage polarity will appear across the tube 31 as the pulse dies out, the breakdown voltage of the tube 31 is such that no current will flow during the latter or trailing portion of each pulse, and hence the current pulses have a D. C. component.

This feature is mentioned at this time because it bears directly on one of the structural improvements of the lamp to be discussed hereinafter.

Referring to Figs. 2 through 8, the physical structure of the lamp embodying the circuit elements shown in Fig. 1 will now be described.

The ground of Fig. 1 is represented by the chassis 23, which is of any suitable conducting sheet material, such as steel, stamped into the desired shape, shown in Fig. 5. Side channels 32 are formed in the edges of the chassis 23 to increase the rigidity. On the upper side of the chassis 23, near the center, is mounted a bifurcated clip 33 formed of a bight portion 34 and a pair of upstanding arms 36 of arcuate cross-section. The bight 34 is secured to the chassis 23 by a hollow iivet or eyelet 37. The clip 33 serves to mount to the chassis the electron discharge tube 31 formed in the shape of a. helix. One end of the tube 31 terminates in an axial leg 38 embraced between the two arms 36 of the clip 33 and further held in place by a resilient or rubber band 39 around the clip 33. The end convolution 41 of the helical tube 31 is formed in a plane normal to the tube axis and resides on an annular base 42 made of sponge rubber or other suitable insulating material. The base 42 is mounted around the clip 33 and interposed between the tube 31 and the chassis 23.

The tube 31 embodies an electrode 43 in each end thereof. The electrode in the axial end 38 is grounded by a conductor 44 which passes directly down through the eyelet 37 and is soldered to the chassis 23 within the eyelet 37 as shown at 46. The electrode in the other end 41 of the tube is connected by means of a conductor 47 to one side of the secondary winding 29 of the transformer 26, passing through an opening in the chassis 23 protected by a rubber grommet 48.

Suspended beneath the chassis plate 23 is a conducting frame 49 of similar material, secured to the chassis 23 by a plurality of tabs 51 which pass through slots 52 in the chassis 23 and are twisted as shown in Fig. 4. The frame 49 is mounted at one side of the chassis 23, one edge of the frame 49 substantially coinciding with the axis of the tube leg 38, as best seen in Fig. .2. Tabs .53 are pressed downwardly out of the chassis 23 to form guides and braces for the said one wall of the .frame 49. To the bottom of the frame 49 is mounted the transformer 26, a portion of the transformer winding being accommodated by an opening 54 in the bottom wall of the frame 49. The transformer 26 is secured .to the frame 43 by bolts 56. Also mounted to the bottom wall of the frame 49, adjacent the core of the transformer 26, by a screw 57, is an L-shaped member .58 which is located in position by means of a transverse lip 59 formed on the end thereof, which engages a slit 61 in the edge of the frame 49. To the extending arm of the member 58 is secured, by a bolt and nut 62, an elongate U-shaped copper member 63 forming one arm of the switch 27. As best seen in Fig. 7, the switch arm 63 is doubled back on itself, and the doubled back portion 64 is caused to bear against the arm 63 to bias the arm 63 resiliently toward, but not completely against, the core of the transformer 26. Secured to the copper arm 63 adjacent the core of the transformer 26, is a strip of magnetic material 66 forming the switch armature.

To the outer wall of the frame 49 is pivotally secured the other switch arm 67 of the switch 27. This arm is secured to an arbor 68 freely journalled in a bearing 69 mounted in an opening 71 in the frame 49. To the inner end of the arbor 68 is secured the inner convolution of a spiral hair spring '72, the outer convolution of which is anchored to an eyelet 73 mounted to the frame 49 but insulated therefrom by a grommet 74 held in an opening 76 in the frame 49. A conductor (not shown) leads from the eyelet 73 to one side of the primary winding 24 of the transformer 26.

The switch arm 67 is counterbalanced on the arbor 68 by having formed integral therewith an opposed arcuate counterweight 77. The hair spring 72 serves to bias the contact point 78 on the end of the arm 67 against the contact point 79 on the end of the arm 63, so that the switch 27 is normally closed. At the same time the hair spring 72 permits the arm 67 to be pivoted (clockwise in Fig. 7) through an arc of almost 360 without overstressing any of the parts of the mechanism.

The capacitor 28 shunts the switch 27 by being connected between the eyelet 73 and a point on the frame 49 representing ground.

Encasing the entire operating mechanism of the lamp is a housing or box 81 (Fig. 6) which is held to the chassis 23 by having the edges of the box 81 clamped over into the channels 32, as shown at 32 in Fig. 4. It will be noted that one edge of the box 81 has a semicircular archway 83 cut therein, which registers with a similar archway 84 in the frame 49. As shown in Figs. '2 and 4, these archways come directly under the rivet 37 and solder connection 46 by which the discharge tube 31 is connected to the chassis 23. Provision of the archways makes it possible to replace the tube 31 without re- .qu'iring access to the .interior of the box '81 and running the risk of disturbing the rather precisely adjusted mechanism of the switch 27. The other connection of the tube is severed merely by forming a splice in the wire 47 connected by a soldered joint 36, as shown in Fig. 2. "When the joints are broken at 86 and 46 it is a simple matter to remove the tube 31 simply by slipping the leg 38 upwardly out of the clip 33.

The electric energy for actuation of the lamp is derived from the dry cell 21, which is of approximately the same size and shape as the box 81, and which occupies the other half of the region beneath the chassis 23. The two terminals 87 of the cell 21 are disposed side by side and diagonally across the top of the cell as shown in Fig. 3. The terminals are of leaf spring construction so that they have a natural bias upwardly against two .Tivets .88 and 89 passing through and insulated from the chassis 23. The rivets are seated in conical depressions 91 formed in the chassis 23, so as to better contact the terminal strips 87. The diagonal disposition of the terminal strips 87 results in a proper connection of the battery to the terminals 88 and 89 irrespective of which of the four possible positions the battery may be placed in.

To the upper end of the rivet 88 is connected a lead '92, the other end of which is connected to the primary winding 24 of the transformer 26. The other rivet 89 constitutes oneof the contact points of the on-oti switch 22, the other contact point of the switch 22 being simply ground or the chassis 23. The switch 22 constitutes one of the features of the instant invention and will be described more fully hereinafter.

for some time.

-Eelectron discharge tubes of the general type represented by the numeral 31 have been known in the art Neon tubes, which are preferred for use in the instant invention, have in the past been used almost entirely for flashing sign purposes, and have been powered by A. C. rather than by an essentially D. C. pulse, as in the instant invention. When powered by A. C. the tube is electrically symmetrical, whereas when powered by a D. C. pulse, as in the instant case, there is an electrical assymmetry, which has been found to produce a serious erraticalness in operation, as will be explained hereinafter. As was explained at the outset, the lamp of the instant invention is designed especially to provide a continual flashing light; to be readily securable to a road barricade; and to flash all night to warn motorists of the danger. When the lamp, including the discharge tube 31, was first put to such all night use, it was found in practice that a number of lamps did not fire regularly but were erratic in their operation. That is, they would flash for a few times and then go off for awhile, and then commence flashing again. Investigation of the electrical part of the system showed that there was no fault in it; the lamp 31 was receiving voltage pulses regularly. It was therefore evident that the cause of the erratic operation lay in the lamp itself, since it was being supplied with voltage at the right time.

It was found that lamps which were erratic at night might, and generally did, work satisfactorily in the day time, or whenever a light was falling upon them, but that as soon as they were placed in the dark they began to operate erratically as mentioned above. From this it was deduced that the external light provided suflicient constant ionization of the gas within the tube to allow even the borderline lamps to operate regularly, but that when such borderline lamps were placed in darkness, without the photometric ionization, they became erratic. It has been discovered in accordance with the instant invention that erratic operation of such lamps may be cured by placing a conductive means, such as a plate or foil of conductingmaterial, outside the tube in intimate contact with the glass of the tube, and as close as possible to the two ends of the tube; and then connecting the two plates to ground. in Figs. 2 and 4, for example, the mounting clip 33, by embracing the axial leg 33' at the extreme end of the tube, provides a good glass-to-metal contact which is well grounded to the chassis 213. At the other extreme end of the tube, namely, the convolution 41, there is placed, in accordance with the instant invention, a strip or sheet of metallic foil 93, which is disposed between the base 42 and the chassis 23, as shown in Fig. 4, and extends around the edge of the base 42, under the end convolution 41, and at least partially around the end convolution 41, thereby providing good conducting contact between the chassis Z3 and the external surface of the glass at extreme end of the tube.

In order to provide a margin of safety, it is preferred to curl the foil 93 partially around the end convolution 41 of the tube, as shown in Fig. 4; but this is not actually necessary for satisfactory operation of the tube. The foil may, if desired, reside simply on top of the base 42 without being brought up around the tube.

Alternatively, the base 42 may be coated with a conducting paint or covering which forms the ground connection and tube-contact-plate, from the bottom surface of the tube convolution 41 around the edge of the base 42 and onto the chassis 23.

by the accumulation of a static electrical charge on the surface of the tube. opposition to the normal voltage differential tending to The polarity of the charge is in fire the tube. After several pulses of current have flowed through the tube, the magnitude of the charge is such that the net potential between the tube electrodes, taking into account the charge on the glass, is insufficient to fire the tube down, and it ceases to fire until the charge has leaked off to the point where it can again fire. By providing the grounding plates, or electrodes, around each end of the tube, the charge is enabled to rapidly dissipate to the chassis 23, and never builds up to the point where it blocks firing of the tube.

The structure above described is not to be confused with the old and well known starting electrode, in which a conducting plate or electrode was placed around one end of the tube only, and then connected to the lead coming out of the other end of the tube. In order to avoid the undesirable erratic operation above discussed, it is absolutely essential, in the instant environment, to embrace both ends of the tubes as near each end as possible, with a grounding clip or plate. One clip only is ineffective for the purpose.

In some cases a discharge tube of the type shown in Fig. 9 is used, in which the two ends of the tube are both parallel to the axis, one on one side of the tube and one on the other. In this case, to the tube 31 is attached, around one of the legs 41 a grounding clip 94, and around the other leg 33' an identical grounding clip 96. These two clips are connected together by a wire 97 and are then grounded to the chassis 23 by a lead 98. The necessity for both clips has also been clearly demonstrated with this type of tube. That is to say, when only the clip 94 is used, the tube is erratic in operation even though the clip 94 is grounded directly to the chassis. Both clips, 94 and 96, must be used for satisfactory operation.

In general, to avoid erratic operation at night, described hereinbefore, the tube must be provided with some form of conducting means contiguous to the respective ends of the tube, and at least partially embracing the outside of the tube in close contact therewith, and that these two conducting means must then be both connected to the ground plate or chassis in which the tube is mounted. I

The assembly shown in Fig. 2 is secured within an outer casing 99 shown in Fig. 11. The casing 99 is provided with a central opening 103 through which the discharge tube 31 protrudes, and in this opening is mounted a transparent plastic or glass dome 101 having a flared bottom edge 102 which cooperates with the flared edge of the opening 103 to retain the dome 101 in place. A rubber gasket 105 is disposed between dome 101 and casing 99 to protect the glass and also seal the opening 103. Extending downwardly from the inside of the casing 99 are a pair of bolts 104 which pass through holes 106 formed in pressed out brackets in the chassis 23. Onto the bolts 104- are threaded nuts 107 which hold the chassis 23 firmly against the top or roof of the casing 99. The open bottom of the casing is closed by a floor or base 108 of suitable construction.

Mounted in and passing through the roof or top of the casing 99 is the on-oif switch 22, seen in detail in Fig. 12. Mounted in and extending through an opening 109 in the casing 99, onto both sides of the casing, is a rubber grommet 111 having a central bore through which passes a short shaft 112. The shaft 112 is rotatable from outside the casing to actuate the switch 22, as will be described presently. The grommet 111 serves as a watertight seal between shaft 112 and opening 109. The upper end of the shaft 112 terminates in a circular, external head 113, the outer surface of which is conical, tapering downwardly from an axial, hexagonal socket 114 to a sharp edge 116 forming the outer periphery of the head 113. The under surface of the head 113 is substantially normal to the axis of the shaft 112, and between the head 113 and the grommet 111 there is placed on and about the shaft 112 and rotatable with respect thereto a steel washer 117 having a diameter larger or greater than that Of the adjacent outer periphery 116 .of the head 113. Under the steel washer 117, between the washer 117 and the grommet 111, is a thin brass Washer 110 of smaller .di ameter than the washer 117. The brass washer gives added pliancy to the abutment between the head 113 and the grommet 111.

Around the bottom end of the shaft 112 and against the under side of the grommet 111 are located, successively, another brass washer 115, and another steel washer 118. Immediately beneath the washer 118 the shaft 112 is relieved and provided with a flat portion, this portion of the shaft mating with a corresponding opening in a leaf-like transverse conducting switch arm 121. The arm 121 is secured against rotational movement on the shaft 112 by the cooperating flat surfaces on the shaft and arm, respectively, mentioned above. To secure the arm 121 firmly against the shoulder formed by the relieved portion of the shaft, a steel washer 119 is placed over the shaft 112 against the under side of the arm 121, and the end of the shaft is then peened over against the washer 119 as shown at 120. An access opening 122 is provided in the chassis 23 in alignment with the shaft 112.

Bothends of the switch arm 121 bear resiliently against the upper surface of the chassis 23. The switch is so located that either end of the arm 121 may be brought into conducting engagement with the rivet 89, the under end of which is in contact with one of the terminals 87 of the cell 21, as described hereinbefore. The arm 121 may also be selectively registered wtih either of a pair of detent holes 123 formed in the chassis 23. These holes serve simply as detents into which the ends of the arm 121 drop slightly as the shaft 112 is rotated. In this way the operator may tell by feel when the switch is in full on or full off position. It is thus seen that a full 90 turn of the shaft 112 serves to operate the switch from on to 011 position, or vice versa, no matter which way the shaft is turned. When the ends of the arm 121 rest in the .detent holes 123, the edges of the arm are still in con- .tact with the chassis 23 at .the edges of the holes 123. By thus grounding the eyelet 89 through the switch arm 121, the lamp is turned on, as may be readily seen by refercnceto Fig. 1.

The hexagonal socket 114 in the head 113 forms a means adapted to receive an actuating tool in the form of a correspondingly shaped hexagonal wrench 124. In this manner the head 113 may be rotated and the switch operated only by a person having the proper shape and size wrench 124, and thus the danger of operation by A mischievous children is greatly lessened. The switch is so constructed that it is virtually impossible to operate it except by the appropriate wrench. A pliers can not .be used, because the flat angle of the conical head 113 preeludes grasping of the head by a pliers. The head can vnot be grasped at the edge 116 because of the larger diameter washer 117 spaced from the casing 99 by the grommet 111. Were one to attempt to grasp the edge 1-16 with .a pliers, he would succeed only in seizing the edge :of .the washer 117 which would turn harmlessly without turning the switch. It will be understood that any .shape of non-circular socket may be used at 114, withacorrespondingly shaped wrench 124.

The lamp described hereinbefore is especially designed to be mounted upon the barricade shown in Fig. 11. The barricade .consists of a .pair of legs 126 and 127 pivoted together by a pivot pin or bolt 128, and a similar pair of legs (not shown) connected to the legs 126 and 127 by horizontal barricade members 129. For storage and transportation it is highly desirable that the legs 126 and 127 be collapsed, i. re., pivoted together, so as to occupy less space. At the same time it is desirable that they be locked in .open or extended position when in use, in order to rendertheir transportation more diflicult to those Who wouldsteal them.

tum is achieved in the following manner. Each of the legs 1 26 and 127 consists of an angle or L-iron, that is, an iron having an angled cross-section. For purposes of identification, each of the legs will be defined as having a body portion 131 and a flange portion 132 formed at right angles thereto. The two body portions 131 are pivoted together at 128 by a pivot pin or bolt, in such a manner that the two flanged portions 132 extend from the body portions in the same direction. Adjacent the pivot pin 128 the legs 126 and 127 are bent outward so that they may be spread apart and still retain appreciable overlapping body portions above the pivot pin 128. The overlapping body portion, in conjunction with the two flanges 132, form somewhat of a pocket or channel above the pivot 128. Through the overlapping portions of the body portions 131, above the pivot 128, are formed registering openings. In the leg 127 the opening 133 is small, being just large enough to accommodate the body of a bolt 138 (see Figs. 13 and 14). In the leg 126 the opening is larger and non-circular-in this case square, as shown at 134.

To the casing 99 of the warning lamp is welded a strengthening plate 136 (Fig. 14), and to the plate 136 is welded a nut 137 having a square periphery adapted to mate into the square opening 134 in the leg 126.

When the legs 126 and 127 are spread apart, as shown in Fig. 11, in such position as to cause the barricade to stand upright, and when the lamp casing 99 is placed in the position shown with the nut 137 in the opening 134, the bolt 138 may be passed through the opening 133 in the leg 127 and screwed into the nut 137. This bolt serves not only to hold the lamp in place firmly on the barricade, but also prevents relative pivoting of the legs 126 and 127. Thus by a single operation the lamp is bolted to the barricade, and the barricade legs are bolted in an extended position.

In order to prevent unauthorized unscrewing and rernoval of the bolt 138, a conventional bolt-head lock 139 is provided. This lock includes an elongate washer-like member 141 interposed between the leg 127 and the head of the bolt 138, and having an upstanding flange portion 142. The flange portion 142, as is well known in the art, has a slot into which may be moved, by arcuate movement, a finger 143 controlled by a lock barrel 144. When the finger 143 is locked to the washer 141, the entire lock 139 is held to the head of the bolt 138, and in so covering the head of the bolt prevents anyone from turning the bolt.

It is conceivable that one might work the bolt 138 loose by turning the lock 139 and washer 141 around and around and thus rely on frictional contact to eventually unscrew the bolt. In accordance with the instant invention, two safeguards are taken to prevent this.

The first of these safeguards consists of the above mentioned pocket formed by the flange portions 132 of the legs 126 and 127. These flanges restrict oscillation of the lock 139 to a very limited arc, and virtually preclude loosening of the bolt by rocking the lock.

In addition, the length of the bolt 138 is so proportioned that the washer 141 is not clamped firmly between the bolt head and the leg 127. Instead the bolt is hottomed firmly at 146 against the strengthening plate 136. Thus the frictional engagement between the washer 141 and the head of the bolt 138 is small, while that between the bottom of the bolt and the plate 136 is great. Hence it would be virtually impossible to loosen the bolt by oscillation, or even continued rotation, of the lock 139, even if the flanges did not make such rotation impossible.

An alternative form of leg structure to that shown in Fig. 11 is illustrated in Fig. 15. In this form the angled legs 126 and 127 are not bent slightly near the pivot point 128',b u t instead the .pivot point 128' is positioned near the end of the legs, and the body portions 131' of the legs are cut on an angle, so that there is sufficient over- In accordance with the instant invention this desidera- -lapping body areabetween the two legs, above the pivot 128, to permit formation of the registering openings 133 and 134, and also permit insertion of the lock 139 in the angular pocket thus formed. The embodiment shown in Fig. is preferred because of the more economical cost of construction.

If desired, the casing 99 of the warning lamp may be provided with tabs 147 welded at each end thereof and provided with chain-receiving holes 148 and loops 149. These enable the lamp to be chained to a suitable standard where the special barricade shown in Figs. 11 and 15 1s not used.

It is to be noted that the entire lamp is completely accessible from the bottom merely by removing the recessed bottom or base 108. This allows the lamp casing to be embedded in a concrete block if desired, with only the bottom 108 exposed at the bottom of the block, and the top of the casing 99 exposed at the top of the block in order to give access to the switch 22 and allow clearance for the dome 101. Such a use is often desirable where the lamp is to be used without a barricade of any type. In this case the holes 148 provide an easy means for the insertion of a carrying handle for transporting the block and lamp.

Barricade structures constructed in accordance with the instant invention have been placed in position around road work, and the lamps have been turned on night and day for weeks without further attention. The duty cycle of the operating mechanism is so s'mallof the order of 1%-that the energy drain on the battery allows the batterv to operate continuously for weeks before becoming ineffective.

While the instant invention has been shown and described herein in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein but is to be accorded the full scope of the claims.

What is claimed is:

1. A switch assembly comprising a casing having an opening therein, a pliant grommet mounted in and extending through said opening onto both sides of said casing and having a bore therethrough, a shaft passing through said bore and rotatably mounted therein, said grommet serving as" a seal between shaft and casing whereby said casing remains substantially water tight at said opening, a switch within said casing linked to said shaft to be operated thereby, a head on the external end of said shaft having a hexagonal socket located substantially centrally therein, a washer mounted rotatably around said shaft and disposed between said head and said grommet, the precence of said grommet spacing said washer from said casing, said head tapering outwardly to a sharp edge contiguous to said washer, the surface of said head adjacent said washer being flat and contiguous to said washer, the surface of said head opposite said washer being conical and tapering in to said socket, said washer being of greater diameter than the adjacent periphery of said head, whereby there is presented by said head no surface which may be grasped by a pliers or like tool.

2. A switch assembly comprising a casing having an opening therein, a pliant grommet mounted in and extending through said opening onto both sides of said casing and having -a bore therethrough, a shaft passing through said bore and rotatably mounted therein, said grommet serving as a seal between shaft and easing whereby said casing remains substantially water tight at said opening, a switch within said casing linked to said shaft to be operated thereby, a head on the external end of said shaft having a non-circular socket located substantially centrally therein, a washer mounted rotatably around said shaft and disposed between said head and said grommet, the presence of said grommet spacing said washer from said casing, the surface of said head facing said washer being flat, the surface of said head opposite said 10 washer being conical and tapering in to said socket, said washer being of greater diameter than the adjacent periphery of said head, whereby there is presented by said head no surface which may be grasped by a pliers or like tool.

3. A switch assembly comprising in combination a casing having an opening therein, a shaft passing through and rotatably mounted in said opening, a switch within said casing linked to said shaft and operable thereby, a circular head secured to the external end of said shaft having a non-circular socket centrally located therein adapted to receive an actuating tool, and a washer disposed on said shaft between said head and said casing and rotatable with respect to said shaft, said head tapering outwardly to a sharp edge contiguous to said washer, said washer having a diameter greater than said head, whereby there is no grasping surface on said head for a pair of pliers or like grasping tool.

4. A switch assembly comprising in combination a casing having an opening therein, a shaft passing through and rotatably mounted in said opening, a switch plate within said casing, a switch terminal mounted on said plate and electrically insulated therefrom, switch arm means mounted transversely on said shaft, and having a portion in resilient contact "with said plate and another portion selectively engageable with said terminal upon rotation of said shaft, thereby to complete a circuit through said arm means between said plate and said terminal, and a circular head on the external end of said shaft having means adapted to receive an actuating tool for rotating said head, the outer periphery of said head tapering to a sharp edge, whereby there is no grasping surface on said head for a pair of pliers or like grasping tool.

5. A shaft actuating device comprising a casing having an opening therein, a pliant grommet mounted in and extending through said opening onto both sides of said casing and having a bore therethrough, a shaft passing through said bore and rotatably mounted therein, said grommet serving as a seal between shaft and easing whereby said casing remains substantially water tight at said opening, a circular head on the external end of said shaft having means adapted to receive an actuating tool for rotating said head a washer mounted rotatably around said shaft and disposed between said head and said grommet, the presence of said grommet spacing said washer from said casing, said head tapering outwardly to a sharp edge contiguous to said washer, said washer being of greater diameter than the periphery of said head, whereby there is presented by said head no surface which may be grasped by a pliers or like tool.

6. A shaft actuating device comprising a frame, a. shaft rotatably mounted in said frame, a circular head secured to said shaft having means adapted to receive an actuating tool for rotating said head, and a washer disposed on said shaft between said head and said frame and rotatable with respect to said shaft, the surface of said head tapering to a sharp outer periphery contiguous to said washer, said washer having a diameter greater than said outer periphery, whereby there is no grasping surface on said head for a pair of pliers or like grasping tool.

References Cited in the file of this patent UNITED STATES PATENTS 459,219 Castor Sept. 8, 1891 970,410 Wilson Sept. 13, 1910 1,143,676 Williams June 22, 1915 1,298,398 Purple Mar. 25, 1919 1,306,141 Ellerd-Styles June 10, 1919 1,684,148 Ronneberger Sept. 11, 1928 2,286,950 :Breedlove June 16, 1942 2,664,473 Brown Dec. 29, 1953 

